1. Field of the Invention
The invention relates generally to the field of utility line installation equipment, and more particularly to an apparatus and method for simplifying the installation of static lines on the tops of utility poles.
2. Description of the Related Art
During installation and repair of utility transmission lines, it is often necessary to string a xe2x80x9cstatic wirexe2x80x9d or xe2x80x9cshield wirexe2x80x9d across the tops of the utility poles. The static wire is connected to the pole by means of a xe2x80x9cstatic bracketxe2x80x9d having a pair of vertical legs which are bolted to the pole near its upper end and extend upwardly past the top of the pole and a horizontal crossbar which is bolted to the upper extremities of the two legs. The static wire is suspended between the top of the pole and the crossbar by a xe2x80x9cshoexe2x80x9d which clamps to the static wire and a clevis which connects the shoe to the crossbar.
Utility wires are strung by pulling them through a pulley or xe2x80x9cstringing dollyxe2x80x9d which is connected to the pole. The stringing dolly holds the wire in place until the wire can be permanently fastened to the pole. Installation of static wire is complicated by the fact that a standard stringing dolly is too large to fit into the space between the crossbar of the static bracket and the top of the pole. A common method of stringing static wire is to fasten the stringing dolly to the crossbar outside of one of the legs, and then to pull the wire through the stringing dolly and tighten it. The lineman must then loosen the bolts holding the crossbar to the legs and completely remove the bolt on the end of the crossbar opposite the dolly. He or she then pivots the crossbar about the remaining bolt, manually lifts the wire over the top of the static bracket, and works it down between the unbolted end of the crossbar and the respective leg until the wire rests on the top of the pole. The lineman then reassembles the static bracket, clamps the shoe to the wire, and then lifts the wire up toward the crossbar and pins the shoe to the clevis.
The previous installation method clearly involves unnecessary steps since the static bracket must be first be installed, then unbolted to insert the static wire, and then reassembled. Previous practice also requires unnecessary manual lifting; first to raise the wire from the stringing dolly over the top of the bracket, and then again to fasten the shoe to the crossbar. This unnecessary exertion on the part of the lineman results in fatigue and can cause physical injury. What is needed is a device which allows the static wire to be installed between the crossbar and the top of the pole without disassembling the static bracket or manually lifting the wire.
The present invention comprises a static wire stringing apparatus for use when stringing static wire to a utility pole, and a method of using the apparatus. The apparatus comprises a body having a base portion and a pair of arms extending from the base portion in generally opposing directions. Each of the arms has a sleeve attached to its distal end, the sleeves having a generally vertical receiver and an upper bearing surface. Each sleeve receives a jackscrew, the jackscrews having lower ends with flanges sized and shaped so as to be receivable by a coupler of a standard stringing dolly. A nut is threaded on each jackscrew proximate its upper end and bears against the respective sleeve upper bearing surface. A jack handle is provided for turning the nuts and thereby raising and lowering the jackscrews.
The apparatus further includes a crossbar retaining structure which is connected to the body base portion and is securable to a crossbar of a utility pole static bracket such that the distal ends of the arms are in alignment with the desired location for connecting the static wire to the crossbar.
In use, the apparatus is secured to the static bracket crossbar by means of the crossbar retaining structure, and a pair of standard stringing dollies are connected to the jackscrew lower end flanges. A free end of the static wire is then pulled through the stringing dollies and through the gap between the upper extremity of the pole and the crossbar. The apparatus holds the static wire in place until it can be tensioned and permanently connected. After the wire is tensioned, the lineman uses the jack handle to turn the nuts and thereby raise the jackscrew lower ends and the attached static wire until it is the proper distance from the crossbar. The static wire is then connected to the crossbar in the usual manner.
In order to remove the apparatus, the lineman uses the jack handle to turn the nuts and thereby lower the static wire until the dollies are no longer supporting it. The static wire is then released from the stringing dollies and the apparatus is removed from the crossbar.
The principal objects and advantages of the present invention include: providing an apparatus for stringing static wire on power poles; providing such an apparatus which allows the static line to be installed without disassembling the respective static bracket, providing such an apparatus which does not require the static line to be manually lifted into position by a lineman; providing such an apparatus which is lightweight; providing such an apparatus which works equally well in conventional and fiber optic applications; providing such an apparatus which gives a lineman adequate room to work while fastening the static line to its respective static bracket and providing such an apparatus which is economical to manufacture, efficient in operation, capable of a long operating life and particularly well-adapted for the proposed usage thereof.